Optical apparatus that prevents displacement of subject images due to an initializing operation

ABSTRACT

An optical apparatus is disclosed which can prevent displacement of subject images due to an initializing operation of the image stabilizing unit from being seen by a photographer through a finder. The apparatus comprises an image-stabilizing unit which includes a movable unit movable for image stabilization and balls movable in conjunction with the movement of the movable unit, and a controller which controls operations of the movable unit. The controller causes the movable unit to perform a specific operation for moving the balls to a specific position in response to mounting of the optical apparatus on another optical apparatus, the specific operation being a different operation from an image stabilization operation of the image-stabilizing unit.

CROSS REFERENCE TO RELATED APPLICATION

This is a divisional of and claims priority from U.S. patent applicationSer. No. 11/608,308 filed Dec. 8, 2006 the content of which isincorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an optical apparatus including aso-called ball-guide image-stabilizing unit.

2. Description of the Related Art

The ball-guide image-stabilizing unit to be installed in aninterchangeable lens or a video camera has been disclosed in JapanesePatent Laid-Open No. H10-319465, for instance. To be more precise,multiple balls are sandwiched between a base member of theimage-stabilizing unit and a movable unit including an imagestabilization lens by using a spring force so as to guide the movableunit in a plane orthogonal to the optical axis by rolling motions of theballs. It is possible, by this configuration, to realize theimage-stabilizing unit of which drive resistance is reduced whileblocking displacement of the movable unit in the optical axis direction.

As for the ball-guide image-stabilizing unit, however, it is desirablethat the balls be placed at initial positions which are at the center ofa range of movement thereof or in the vicinity thereof before startingan image stabilization operation. The image-stabilizing unit of JapanesePatent Laid-Open No. H10-319465 has the balls housed in a concaveportion for limiting the range of movement formed on the base member.And in a state where the balls have moved greatly from the initialpositions and are in contact with a sidewall surface of the concaveportion, the balls hardly roll due to friction with the sidewallsurface. Thus, drive resistance of the movable unit increases. In manycases, such a deviation of the balls from the initial positions occurswhen an impact is brought on a lens apparatus.

For this reason, Japanese Patent Laid-Open No. 2001-290184 and JapanesePatent Laid-Open No. 2002-196382 have disclosed a technique of, beforecausing the ball-guide image-stabilizing unit to perform an imagestabilization operation, causing it to perform an initializing operationof driving the movable unit to mechanical ends in two mutuallyorthogonal directions, that is, vertical and horizontal directions, andthen returning it to a movable center position. It is thereby possibleto reset the balls at the initial positions of the range of movementwhatever positions in the range of movement the balls are initially at.

Japanese Patent Laid-Open No. 2002-196382 has proposed that theinitializing operation of ball positions should be performedsubsequently to or simultaneously with a reset operation of zooming orfocusing at the time of power-on. It also proposes the initializingoperation should be performed in a state other than during use of animage-pickup apparatus (during monitor observation of a picked up imageor recording thereof).

In the case where a photographer observes a subject through a finder inreal time as with a single-lens reflex camera system, displacement of asubject image due to the initializing operation is observed if theinitializing operation of the ball positions is performed duringobservation of the finder. Therefore, there is a possibility of givingthe photographer a sense of discomfort.

Even if the initializing operation is performed in a state other thanusing an image-pickup apparatus, there is a possibility that the ballpositions deviate from the initial positions due to an impact during theuse or the like after the power-on of the image-pickup apparatus.

BRIEF SUMMARY OF THE INVENTION

The present invention provides an optical apparatus which can preventdisplacement of subject images due to the initializing operation of theimage stabilizing unit (ball positions) from being seen by aphotographer through the finder.

The present invention in its first aspect provides an optical apparatuswhich comprises an image-stabilizing unit including a movable unitmovable for image stabilization and balls movable in conjunction withthe movement of the movable unit, and a controller which controlsoperations of the movable unit. The controller causes the movable unitto perform a specific operation for moving the balls to a specificposition in response to mounting of the optical apparatus on anotheroptical apparatus, the specific operation being a different operationfrom an image stabilization operation of the image-stabilizing unit.

The present invention in its second aspect provides an optical apparatuswhich comprises an image-stabilizing unit including a movable unitmovable for image stabilization and balls movable in conjunction withthe movement of the movable unit, and a controller which controlsoperations of the movable unit. The controller causes the movable unitto perform a specific operation for moving the balls to a specificposition in a state where a power switch of the optical apparatus oranother optical apparatus on which the optical apparatus is mounted isoff, the specific operation being a different operation from an imagestabilization operation of the image-stabilizing unit.

The present invention in its third aspect provides an optical apparatuswhich comprises an image-stabilizing unit including a movable unitmovable for image stabilization and balls movable in conjunction withthe movement of the movable unit, and a controller which controlsoperations of the movable unit. The controller causes the movable unitto perform a specific operation for moving the balls to a specificposition in response to replacement of a power supply on the opticalapparatus or another optical apparatus on which the optical apparatus ismounted, the specific operation being a different operation from animage stabilization operation of the image-stabilizing unit.

The present invention in another aspect provides an image-pickup systemwhich comprises the above-mentioned optical apparatus, and animage-pickup apparatus on which the optical apparatus is mounted andwhich includes a finder for observing a subject image formed by theoptical apparatus.

Other objects and features of the present invention will become readilyapparent from the following description of the preferred embodimentswith reference to accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram showing a configuration of a single-lensreflex image-pickup system, which is the first embodiment of the presentinvention;

FIG. 2 is a sectional view of an image-stabilizing unit mounted on aninterchangeable lens constituting the image-pickup system of the firstembodiment;

FIG. 3 is an exploded perspective view of the image-stabilizing unit ofthe first embodiment;

FIG. 4 is an exploded perspective view of the image-stabilizing unit ofthe first embodiment;

FIGS. 5A to 5D are diagrams describing a guide portion by means of ballsof the image-stabilizing unit of the first embodiment;

FIG. 6 is a flowchart showing an operation sequence of the image-pickupsystem of the first embodiment;

FIG. 7 is a block diagram showing the configuration of the single-lensreflex image-pickup system, which is the second embodiment of thepresent invention;

FIG. 8 is a flowchart showing the operation sequence of the image-pickupsystem of the second embodiment;

FIG. 9 is a block diagram showing the configuration of the single-lensreflex image-pickup system, which is the third embodiment of the presentinvention;

FIG. 10 is a flowchart showing the operation sequence of theimage-pickup system of the third embodiment;

FIG. 11 is a flowchart showing the operation sequence of the single-lensreflex image-pickup system, which is the fourth embodiment of thepresent invention;

FIG. 12 is a front view showing a modified example of theimage-stabilizing unit of the first embodiment;

FIG. 13 is a side view showing the modified example of theimage-stabilizing unit of the first embodiment; and

FIG. 14 is a front view showing another modified example of theimage-stabilizing unit of the first embodiment.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, preferred embodiments of the present invention will bedescribed with reference to the accompanying drawings.

[First Embodimen]

FIG. 1 shows the configuration of a single-lens reflex image-pickupsystem, which is the first embodiment of the present invention.Reference numeral 101 denotes a camera body (hereinafter, simplyreferred to as a camera) as an image-pickup apparatus which is anotheroptical apparatus constituting the image-pickup system. Referencenumeral 111 denotes an interchangeable lens (hereinafter, simplyreferred to as a lens hereafter) as a lens apparatus which is an opticalapparatus constituting the image-pickup system, and it is detachablymounted on the camera 101.

First, the configuration on the camera 101 will be described. A finderoptical system 106 is provided in the camera 101. There is also a quickreturn mirror 107 provided therein, which is an optical element movableto a down position (first position) for guiding a luminous flux from thelens 111 to the finder optical system 106 and an up position (secondposition) for moving out of an optical path from the lens 111.

The camera 101 is also provided therein with a photometric part, notshown, for measuring the amount of light from the lens 111 and animage-pickup element 103 such as a CCD sensor or a CMOS sensor forphotoelectrically converting a subject image formed by the lens 111.Reference numeral 123 denotes a shutter for controlling exposure of theimage-pickup element 103, and 124 denotes a display device provided on abackside of the camera 101.

An image-pickup signal outputted from the image-pickup element 103 isinputted to an image processing circuit not shown, where an image signalis generated based on the image-pickup signal. When a first strokeswitch (SW1) 129 a is turned on by half pressing a release switch, notshown, the camera 101 enters an image-pickup preparatory state in whichphotometry, AF and the like are performed. When a second stroke switch(SW2) 129 b is turned on by fully pressing the release switch, theshutter 123 performs an opening and closing action and the image signalis generated based on the output from the image-pickup element 103. Theimage signal is recorded on a recording medium (a semiconductor memory,an optical disk or the like), not shown, and displayed on the displaydevice 124.

Furthermore, the camera 101 is provided therein with a focus detectioncircuit (not shown) for detecting a focus state of an image-pickupoptical system in the lens 111 based on an output signal from theimage-pickup element 103. Reference numeral 126 denotes an image-pickupmode selection switch. The image-pickup mode selection switch 126 isoperated to select a single image-pickup mode and a continuousimage-pickup mode.

Various operations of the camera 101 are controlled by a camera controlmicrocomputer 102. The camera 101 is provided with a cameracommunication microcomputer 105 for performing a serial communicationwith the lens 111.

The camera 101 and the lens 111 are also electrically connected viaelectric contacts 150. The camera communication microcomputer 105performs communication with the lens 111 via a communication contact ofthe electric contacts 150. The camera 101 is provided therein with apower supply 104. Electric power from the power supply 104 is suppliedto each of the portions in the camera 101, and is also supplied to thelens 111 via a power supply contact of the electric contacts 150.

Next, the configuration of the lens 111 will be described. Referencenumeral 120 denotes a lens unit including a magnification varying lens,a focus lens, a stop unit and the like. Reference character L1 denotes acorrection lens as an image stabilization optical element. The lens unit120 and correction lens L1 constitute an image-pickup optical system.

The correction lens L1 moves in the directions (pitch direction and yawdirection) orthogonal to the optical axis of the image-pickup opticalsystem (lens unit 120) and thereby performs image-shake correction(image stabilization) of the subject image formed on the image-pickupelement 103 by the image-pickup optical system in the pitch directionand yaw direction. The directions orthogonal to the optical axisreferred to here include not only the direction completely orthogonal tothe optical axis but also the directions which can be optically regardedas orthogonal to the optical axis. The pitch direction corresponds tothe vertical direction, and the yaw direction corresponds to thehorizontal direction.

Reference numeral 112 denotes a lens control microcomputer whichperforms drive control of the magnification varying lens, focus lens andstop unit. The lens control microcomputer 112 performs a serialcommunication with the camera 101 via a lens communication microcomputer113.

Reference numeral 115 denotes an image stabilization (IS) controlmicrocomputer for controlling the operation of an image stabilizationactuator 116 which drives the correction lens L1. The imagestabilization actuator 116 is composed of a coil, a magnet and a yoke aswill be described later. An image-stabilizing unit 200 is composed of amovable unit including the image stabilization actuator 116 and thecorrection lens L1, a base member which holds the movable unit movablein the pitch direction and yaw direction and the balls which guidesmovement of the movable unit. A concrete configuration of theimage-stabilizing unit 200 will be described later. A controller isconfigured by the lens control microcomputer 112 and the imagestabilization control microcomputer 115.

Furthermore, the lens 111 is provided therein with a shake sensor 117for detecting shake, such as hand shake, of the lens 111 and the entireimage-pickup system. The shake sensor 117 is composed of an angularvelocity sensor, an acceleration sensor or the like, and outputs anelectrical signal according to the shakes in the pitch direction and yawdirection.

Reference numeral 125 denotes an image stabilization (IS) switch forselecting whether or not the image stabilization operation is performed.

Though not shown, the lens 111 is further provided with a stop actuator,a stop driver, a focus actuator, a focus driver, a focus positiondetector, a zoom operating ring and a zoom position detector.

Next, the operation of each of the components will be described. Thestop driver drives the stop actuator according to a command from thelens control microcomputer 112 and activates the stop unit. The focusdriver drives the focus actuator according to a command from the lenscontrol microcomputer 112 so as to drive the focus lens in the opticalaxis direction.

The image stabilization control microcomputer 115 drives the imagestabilization actuator 116 (that is, the correction lens L1) based onthe output signal from the shake sensor 117.

When the zoom operating ring is operated, the magnification varying lensis driven in the optical axis direction by a zoom drive mechanism, notshown. The zoom position detector outputs a digital signal (zoomposition signal) corresponding to a divided area of the zoom rangebetween the wide-angle end and the telephoto end, which is divided intoa predetermined number of areas. The focus position detector outputs adigital signal (focus position signal) corresponding to a divided areaof the focus range between the closest position and the infiniteposition, which is divided into a predetermined numbers of areas.

These zoom position signal and focus position signal are used in orderto obtain focal length information and focus position informationnecessary to accurately perform calculation for AF in a TTL passivemethod which is the most commonly used single-lens reflex automaticfocus (AF) method. The lens control microcomputer 112 reads datanecessary for the calculation for AF out of table data stored on an ROMin the lens control microcomputer 112 based on the focal lengthinformation and focus position information. The data are transmitted tothe camera 101, and the camera control microcomputer 102 having read thedata performs a predetermined calculation for AF. The camera controlmicrocomputer 102 transmits a focus drive command obtained as a resultof the calculation for AF to the lens 111. The lens controlmicrocomputer 112 drives the focus lens according to the focus drivecommand.

Next, the concrete configuration of the image-stabilizing unit 200 ofthis embodiment will be described by using FIGS. 2 to 4. FIG. 2 is asectional view of the image-stabilizing unit 200. FIGS. 3 and 4 areexploded perspective views of the image-stabilizing unit 200 when viewedfrom a front side and a rear side, respectively.

The image-stabilizing unit 200 of this embodiment does not include alock mechanism for keeping the movable unit at a center position whennot using the image-stabilizing unit 200 (when the image stabilizationswitch 125 in FIG. 1 is off). The center position of the movable unitused here is the position at which an optical axis center of thecorrection lens L1 coincides with or can be optically regarded ascoinciding with the optical axis of the lens unit 120 as a portion otherthan the correction lens L1 of the image-pickup optical system.

The image-stabilizing unit 200 includes a pitch direction imagestabilization actuator for driving the movable unit (correction lens L1)in a pitch direction P and a yaw direction image stabilization actuatorfor driving it in a yaw direction Y. The image-stabilizing unit 200 alsoincludes a pitch-direction position detecting system for detecting theposition of the movable unit in the pitch direction P and ayaw-direction position detecting system for detecting the position inthe yaw direction Y. Both the image stabilization actuators and both theposition detecting systems have the same configurations, respectively,while only their placements are different by 90 degrees around theoptical axis. For this reason, the image stabilization actuators and theposition detecting systems will hereinafter be described only relatingto the pitch direction P.

In the drawings, the components indicated by the symbols with asubscript p relate to the pitch direction while the components indicatedby the symbols with a subscript y relate to the yaw direction.

Reference numeral 13 denotes a base member which is a fixed member onthe front side of the image-stabilizing unit 200, and it is fixed on thebody of the lens 111. Reference numeral 14 denotes a compression coilspring which is formed by a material not attracted by magnets forposition detection and driving placed in proximity thereto, describedlater, such as a phosphor bronze line. An end 14 a of the compressioncoil spring 14 is bent outward in a radial direction of the compressioncoil spring 14.

Reference numeral 15 denotes a shift lens-barrel for holding thecorrection lens L1. An end of the compression coil spring 14 on thefront side in the optical axis direction is engaged with the shiftlens-barrel 15 so as to be approximately coaxial with the optical axisof the correction lens L1. The end 14 a of the compression coil spring14 is engaged with a V-groove portion 15 d formed on the shiftlens-barrel 15.

Reference numerals 16 a, 16 b and 16 c denote three balls sandwichedbetween the base member 13 and the shift lens-barrel 15. Each ball isformed by the material not attracted by the magnet for driving placed inproximity thereto, such as SUS 304 (austenite stainless steel). Thesurfaces in contact with the balls 16 a, 16 b and 16 c are surfaces 13a, 13 b and 13 c on the base member 13, respectively, and are surfaces15 a, 15 b and 15 c on the shift lens-barrel 15, respectively. Each ofthe contact surfaces is a plane orthogonal to the optical axis of theimage-pickup optical system.

In the case where outside diameters of the three balls 16 a, 16 b and 16c are the same, it is possible to reduce the difference among thedistances between the contact surfaces opposite to each other in theoptical axis direction at three locations. This makes it possible toguide the movement of the correction lens L1 while maintaining itsposition which is orthogonal to the optical axis.

Reference numeral 17 denotes a sensor base as a fixed member on the rearside, which is positioned by two positioning pins and coupled to thebase member 13 by two screws. A rear end of the compression coil spring14 is engaged with the sensor base 17, and is fixed on the sensor base17 by adhesion or the like. The compression coil spring 14 is compressedbetween the shift lens-barrel 15 and the sensor base 17. Thus, thecontact surfaces of the shift lens-barrel 15 and the base member 13 arebrought into contact with the three balls 16 a, 16 b and 16 c withpressure.

A lubricant is placed between the three balls 16 a, 16 b and 16 c andthe contact surfaces. The lubricant has a sufficient degree of viscosityto prevent the balls from easily dropping off the contact surfaces evenin a state where the balls are not sandwiched between the base member 13and the shift lens-barrel 15. Thus, an inertia force exceeding thebiasing force of the compression coil spring 14 acts on the shiftlens-barrel 15, which prevents the ball positions from easily deviatingeven if the balls are put in a non-sandwiched state.

Next, the configuration of the pitch direction image stabilizationactuator will be described. Reference numeral 18 p denotes a drivingmagnet which is two-pole-magnetized in a radiating direction from theoptical axis. Reference numeral 19 p denotes a yoke for closing amagnetic flux on the front side in the optical axis direction of thedriving magnet 18 p. Reference numeral 20 p denotes a coil fixed on theshift lens-barrel 15 by adhesion.

Reference numeral 21 denotes a yoke for closing a magnetic flux on therear side in the optical axis direction of the driving magnet 18 p. Theyoke 21 is fixed on the base member 13 with magnetism so as to formspace with the driving magnet 18 p for allowing a coil 20 p to move.Thus, a closed magnetic circuit is formed.

When the coil 20 p is energized, a Lorentz force is generated in thedirection approximately orthogonal to the magnetization boundary of thedriving magnet 18 p due to mutual repulsion of magnetic field linesgenerated between the driving magnet 18 p and the coil 20 p, therebymoving the shift lens-barrel 15. This configuration is referred to as aso-called moving coil type.

The image-stabilizing unit 200 has the yaw direction image stabilizationactuator of the same configuration as the pitch direction imagestabilization actuator placed therein. It is thereby possible to drivethe movable unit composed of the correction lens L1 and the shiftlens-barrel 15 in the pitch direction and the yaw direction which areorthogonal to the optical axis and mutually orthogonal.

Here, a description will be made of the relationship between the basemember 13 and the movable unit (shift lens-barrel 15) with respect tothe ball 16 b by using FIGS. 5A to 5D. The same relationship is appliedto the other balls 16 a and 16 c.

In FIG. 5A, the shift lens-barrel 15 is at a movable center positionthereof (the position at which the optical axis of the correction lensL1 coincides or substantially coincides with the optical axis of thelens unit 120). The ball 16 b is also located at the center of the ballmovement range limited by a frame 13 d formed around the contact surface13 b of the base member 13. The frame 13 d is a limiting portion toprevent the ball 16 b from moving beyond the ball movement range.

FIG. 5B shows the state in which the shift lens-barrel 15 is driven in adown-pointing arrow direction from this state. The shift lens-barrel 15is driven to a mechanical end, not shown, provided on the base member13, and is moved by ‘a’ from the movable center position.

As the ball 16 b is sandwiched by the base member 13 and the shiftlens-barrel 15, it rolls from the position of FIG. 5A in the arrowdirection and moves to a position shown in FIG. 5B. Rolling friction ofthe ball 16 b is small enough as compared with sliding friction, so thatthere is no slip between the ball 16 b and the contact surfaces 13 b, 15b. For this reason, the shift lens-barrel 15 moves with respect to thebase member 13 while guided by rolling of the ball 16 b. In this case,the shift lens-barrel 15 and the base member 13 move in relativelyopposite directions to the center of the ball 16 b. Therefore, themovement amount of the ball 16 b to the base member 13 is a half themovement amount of the shift lens-barrel 15. To be more specific, themovement amount ‘b’ of the ball 16 b is a half of ‘a’, that is, (a÷2) asshown in FIG. 5B.

FIG. 5C shows the base member 13 and the ball 16 b when viewing thestate of FIG. 5A from the rear side in the optical axis direction. Theball 16 b is located at the center of the movement range in the pitchdirection and yaw direction. The frame 13 d is shown around the ball 16b and the contact surface 13 b. The distance between internal surfacesof the frame 13 d, that is, a size of the ball movement range in thepitch direction and yaw direction is represented by (r+b+c) from thecenter when the radius of the ball 16 b is ‘r’. Reference character cdenotes a mechanical margin amount.

In the case where the ball 16 b is at a position deviating from thecenter of the ball movement range shown in FIG. 5C by ‘c’ or more, whenthe shift lens-barrel 15 is driven as shown in FIG. 5B, the ball 16 bcontacts the internal surfaces of the frame 13 d before the shiftlens-barrel 15 moves by ‘a’ and contacts the mechanical end. After theball 16 b contacts the internal surfaces of the frame 13 d, the shiftlens-barrel 15 is driven to the mechanical end while sliding against theball 16 b. When the shift lens-barrel 15 is returned to the movablecenter position from this state, the ball 16 b returns by rolling to theposition at the distance of ‘c’ from the center of the ball movementrange.

Thus, when the shift lens-barrel 15 is returned to the movable centerposition after being driven to the mechanical end, the center of theball 16 b is located within a rectangular area having sides of distances‘c’ from the center of the ball movement range whatever position theball 16 b is initially at as shown in FIG. 5D. To be more specific, theball 16 b returns to an initial position (reset position) in thevicinity of the center of the ball movement range.

This series of operations are referred to as a reset operation(initializing operation or specific operation) of the balls in thisembodiment. The initializing operation is performed as a differentoperation from an image stabilization operation of the image-stabilizingunit 200 based on the output of the shake sensor 117.

If the shift lens-barrel 15 is moved by the same distance in the pitchdirection and the yaw direction, the shift lens-barrel 15 moves to theposition of √2 times a drive amount of each direction in the directionat 45 degrees to the pitch direction and the yaw direction. For thisreason, the shift lens-barrel 15 is not driven completely independentlyin the pitch direction and the yaw direction in an actual usage state,but is driven in reflection of the position in the other direction in abarrel movement range of a circular shape or an almost circularpolygonal shape which is centered on the optical axis. The three balls16 a, 16 b and 16 c perform rolling motion in a range having a shapesimilar to the shape of the barrel movement range and a half sizethereof.

The ball movement range has a rectangular shape with the two sidesparallel to the pitch direction and the two sides parallel to the yawdirection. If the ball movement range has the circular shape or thepolygonal shape according to the movable range of the balls in theabove-mentioned actual usage state, there are the cases where the ballsdo not move to the positions for contacting the frame 13 d and so acorrect reset operation cannot be performed, which is not desirable.

In this embodiment, the ball movement range has a rectangular shape twosides parallel to the pitch direction and the two sides parallel to theyaw direction. The ball movement range is set such that, when the ballis biased to two adjacent sides (corners) in the ball movement range(frame 13 d), a gap between the ball and the other two sides becomes alittle larger than a half of the mechanical maximum movement amount orthe maximum movement amount in actual use of the shift lens-barrel 15 inthe direction toward the other two sides. If a ball reset operation isperformed under such a setting, the ball does not contact the frame 13 din actual use so that the shift lens-barrel 15 can be guided just byrolling of the ball.

As previously described, it is possible, by placing the lubricantbetween the balls and the contact surfaces, to reduce the slidingfriction between the balls and the contact surfaces so as to lesseninfluence over position control of the movable unit.

This embodiment described the case of providing the frame 13 d forlimiting the ball movement range on the base member 13. However, it mayalso be provided on the shift lens-barrel 15. This embodiment alsodescribed the case of using the three balls. However, the number of theballs is not limited to this according to the present invention.

In FIGS. 2 to 4, reference numerals 22 p and 22 y denote detectingmagnets which are two-pole-magnetized in a radiating direction from theoptical axis. Reference numerals 23 p and 23 y denote yokes for closingmagnetic fluxes placed on the front side of the detecting magnets 22 pand 22 y. The detecting magnets 22 p, 22 y and the yokes 23 p, 23 y arefixed on the shift lens-barrel 15.

Reference numeral 24 p denotes a hall element for converting a change inmagnetic flux density to an electrical signal, which is positioned andfixed on the sensor base 17.

Reference numeral 25 denotes a flexible substrate for electricallyconnecting the coil 20 p and hall element 24 p constituting thepitch-direction position detecting system to an external circuit. Theflexible substrate 25 is folded back at the portion of reference numeral25 a. The hall element 24 p is mounted on the front side in the opticalaxis direction of the portion of reference numeral 26 p.

The folded-back portion further has three bending portions, where a pin29 p formed on the shift lens-barrel 15 is inserted into an opening 28 pformed at a tip 27 p of the bending portion. The tip 27 p is rotatablearound the pin 29 p. Furthermore, terminals of the coil 20 p aresoldered on land portions 30 p, 31 p provided on the tip 27 p. Theyaw-direction position detecting system is composed of a coil 20 y and ahall element 24 y fixed on the sensor base 17 which are alsoelectrically connected to the external circuit by the flexible substrate25.

Reference numeral 32 denotes a retainer plate for fixing the flexiblesubstrate 25 on the sensor base 17, which is fixed on the sensor base 17with one screw.

In the image-pickup system configured as above, one of the timings whenthe photographer is not observing the subject through the finder opticalsystem 106 is when the lens 111 is mounted on the camera 101.

FIG. 6 shows a flowchart of an initializing operation sequence of thelens 111 (the lens control microcomputer 112 and image stabilizationcontrol microcomputer 115) in this embodiment. The operation isperformed according to a computer program stored in each of themicrocomputers. This also applies to the other embodiments describedlater.

The lens 111 may be mounted on the camera 101 irrespective of whether amain switch (power switch) 122 of the camera 101 is on (power-on) or off(power-off). For this reason, the following operation is performedirrespective of whether the power of the camera 101 is on or off in thisembodiment.

In step (described as ‘S’ in the drawing) 1000, the lens controlmicrocomputer 112 determines whether or not communication of a lens IDhas been performed to the camera control microcomputer 102. The lens IDis necessary information for the sake of identifying a model of themounted lens and performing lens control (focus control and stopcontrol) corresponding to the model. The communication of the lens ID isinitial communication which is initially performed between the lens 111and the camera 101 after the lens 111 is mounted on the camera 101. Forthis reason, the lens control microcomputer 112 can recognize that thelens 111 is normally mounted on the camera 101 by determining that thecommunication of the lens ID has been performed.

If determined that the communication of the lens ID has been performed,the process proceeds to step 1001. If determined that no communicationof the lens ID has been performed, the process repeats 51000.

In step 1001, the lens control microcomputer 112 transmits a controlsignal for having the image stabilization control microcomputer 115perform the initializing operation of the image-stabilizing unit 200irrespective of the state of the image stabilization switch 125.

In step 1002, the image stabilization control microcomputer 115transmits a driving signal to the image stabilization actuator 116 tohave the image-stabilizing unit 200 perform the image stabilizationinitializing operation.

After the initializing operation is thus performed, the imagestabilization operation of the image-stabilizing unit 200 is started ifthe image stabilization switch 125 is turned on and the first strokeswitch (SW1) 129 a is turned on on the camera 101.

As described above, according to this embodiment, the initializingoperation of the image-stabilizing unit 200 (ball positions) isperformed in response to the mounting of the lens 111 on the camera 101,so that it is possible to prevent displacement of the subject image dueto the initializing operation from being seen by the photographerthrough the finder optical system 106.

[Second Embodiment]

FIG. 7 shows the configuration of the interchangeable lens constitutingthe single-lens reflex image-pickup system which is the secondembodiment of the present invention. The basic configuration of theimage-pickup system of this embodiment is the same as that of theimage-pickup system of the first embodiment. For this reason, thecomponents in common are given the same reference symbols as in thefirst embodiment.

However, an image-stabilizing unit 200′ of this embodiment includes alock mechanism 130 for holding the movable unit at the center positionwhen the image-stabilizing unit 200′ is not in use (in the case wherethe image stabilization switch 125 is off). The lock mechanism 130performs a lock operation for locking the movable unit and an unlockoperation for unlocking it by means of a lock actuator which is notshown.

FIG. 8 shows a flowchart of the initializing operation sequence of thelens 111 (the lens control microcomputer 112 and the image stabilizationcontrol microcomputer 115) of this embodiment.

In step 2000, the lens control microcomputer 112 determines whether ornot communication of a lens ID has been performed to the camera controlmicrocomputer 102 as in the first embodiment (step 1000 of FIG. 6). Ifdetermined that the communication of the lens ID has been performed, theprocess proceeds to step 2001. If determined that no communication ofthe lens ID has been performed, the process repeats step 2000.

In step 2001, the lens control microcomputer 112 transmits a controlsignal for performing the initializing operation of theimage-stabilizing unit 200′ to the image stabilization controlmicrocomputer 115 irrespective of the state of the image stabilizationswitch 125.

In step 2002, the image stabilization control microcomputer 115transmits a driving signal to the lock actuator to have an unlockingoperation of the lock mechanism 130 performed.

Next, in step 2003, it is determined whether or not the unlockingoperation of the lock mechanism 130 has been completed. Completion ofthe unlocking operation is determined by, for example, detecting whetheror not a member constituting the lock mechanism 130 have moved to anunlock position by means of a photo interrupter. If the unlockingoperation is completed, the process proceeds to step 2004. If notcompleted, the process returns to step 2002.

In step 2004, the image stabilization control microcomputer 115transmits a driving signal to the image stabilization actuator 116 tohave the image-stabilizing unit 200′ perform the initializing operation.The initializing operation is the same as that described in the firstembodiment.

After the initializing operation is thus performed, the imagestabilization operation of the image-stabilizing unit 200 is started ifthe image stabilization switch 125 is turned on and the first strokeswitch (SW1) 129 a is turned on on the camera 101.

As described above, according to this embodiment, the unlocking andinitializing operations of the image-stabilizing unit 200′ are performedin response to the mounting of the lens 111 on the camera 101, so thatit is possible to prevent displacement of the subject image due to theinitializing operation from being seen by the photographer through thefinder optical system 106.

The first and second embodiments described the cases where theinitializing operation of the image-stabilizing unit is performed inresponse to the initial communication performed immediately aftermounting the lens on the camera. However, a trigger of the initializingoperation of the present invention is not limited thereto. For instance,the initializing operation of the image-stabilizing unit may beperformed in response to a detection signal form a switch for detectingthe mounting of the lens on the camera, which is provided on the lens orthe camera.

[Third Embodiment]

FIG. 9 shows the configuration of the single-lens reflex image-pickupsystem which is the third embodiment of the present invention. The basicconfiguration of the image-pickup system of this embodiment is the sameas that of the image-pickup system of the first embodiment. For thisreason, the components in common are given the same reference symbols asin the first embodiment.

However, a camera 101′ of this embodiment is loaded with a backupbattery 140. The backup battery 140 supplies the electric power foroperating the camera control, lens control and image stabilizationcontrol microcomputers 102, 112 and 115 when the main switch 122 whichis the power switch of the camera 101′ is in an off (power-off) state.

In this embodiment, the initializing operation of the image-stabilizingunit 200 is performed when a certain time elapses after the main switch122 is switched from on to off.

To be more precise, when the camera control microcomputer 102 determinesthat the main switch 122 is off and a certain time period has elapsedafter switching to off, it performs communication to notify the lenscontrol microcomputer 112 thereof. The lens control microcomputer 112having received the communication causes the initializing operation ofthe image-stabilizing unit 200 to be performed via the imagestabilization control microcomputer 115. The initializing operation ofthe image-stabilizing unit 200 is the same as the description in thefirst embodiment.

Next, the operation sequence of the above-mentioned camera 101′ and thelens 111 will be described by using the flowchart of FIG. 10. The flowenclosed by a dotted frame on the left side of FIG. 10 shows theoperation sequence of the camera 101′ (camera control microcomputer102). The flow enclosed by the dotted frame on the right side shows theoperation sequence of the lens 111 (lens control microcomputer 112 andimage stabilization control microcomputer 115).

In step 3000, the camera control microcomputer 102 determines whether ornot the main switch 122 is switched from on to off. If switched from onto off, the process proceeds to step 3001. If not switched (in the caseof on), the process returns to step 3000.

In step 3001, the camera control microcomputer 102 starts a timer countby using its internal clock counter (not shown).

Next, in step 3002, the camera control microcomputer 102 determineswhether or not the timer count of the certain time period has beencompleted (the certain time period has elapsed). If completed, theprocess proceeds to step 3003. If not completed, the process repeatsstep 3002.

In step 3003, the camera control microcomputer 102 determines whether ornot the backup battery 140 or the power supply 104 has sufficientelectric power to have the image-stabilizing unit 200 perform theinitializing operation. In the case of having the sufficient electricpower, the process proceeds to step 3004. In the case of not having thesufficient electric power, this flow is finished.

In step 3004, the camera control microcomputer 102 transmits to the lenscontrol microcomputer 112 a signal indicating that the certain timeelapsed after switch-off of the main switch 122. The signal transmittedin this case may be a command signal for directing the initializingoperation of the image-stabilizing unit 200.

In step 3005, the lens control microcomputer 112 receives the signalfrom the camera control microcomputer 102.

In step 3006, the lens control microcomputer 112 transmits a controlsignal for having the image stabilization control microcomputer 115perform the initializing operation of the image-stabilizing unit 200irrespective of the state of the image stabilization switch 125.

In step 3007, the image stabilization control microcomputer 115transmits a driving signal to the image stabilization actuator 116 tohave the image-stabilizing unit 200 perform the initializing operation.

As described above, according to this embodiment, the initializingoperation of the image-stabilizing unit 200 is performed in the statewhere the main switch 122 of the camera 101 is off, that is, in thestate where the photographer normally does not perform the finderobservation of the subject. Therefore, it is possible to preventdisplacement of the subject image due to the initializing operation frombeing seen by the photographer.

[Fourth Embodiment]

The flowchart of FIG. 11 shows the initializing operation sequence ofthe image-stabilizing unit of the single-lens reflex image-pickup systemwhich is the fourth embodiment of the present invention. The basicconfiguration of the image-pickup system of this embodiment is the sameas that of the image-pickup system of the first embodiment. For thisreason, the components in common are given the same reference symbols asin the first embodiment.

In step 4000, the camera control microcomputer 102 determines whether ornot the power supply (main battery) 104 loaded on the camera 101 hasbeen replaced. If replaced, the process proceeds to step 4001. If notreplaced, the process returns to step 4000. It can be determined thatthe power supply 104 has been replaced from the fact that supply of theelectric power to the camera control microcomputer 102 from the powersupply 104 was stopped once and is then restarted. It may also bedetermined from the fact that a power loading switch, not shown, becameoff once (the power supply 104 was removed) and then became on again(the power supply 104 was loaded).

In step 4001, the camera control microcomputer 102 transmits a signalindicating that the power supply 104 has been replaced to the lenscontrol microcomputer 112. The signal transmitted in this case may bethe command signal for directing the initializing operation of theimage-stabilizing unit 200.

In step 4002, the lens control microcomputer 112 receives the signalfrom the camera control microcomputer 102.

In step 4003, the lens control microcomputer 112 transmits a controlsignal for having the image stabilization control microcomputer 115perform the initializing operation of the image-stabilizing unit 200irrespective of the state of the image stabilization switch 125.

In step 4004, the image stabilization control microcomputer 115transmits a driving signal to the image stabilization actuator 116 tohave the image-stabilizing unit 200 perform the image stabilizationinitializing operation.

As described above, according to this embodiment, the initializingoperation of the image-stabilizing unit 200 is performed when the powersupply 104 of the camera 101 is replaced, that is, in the state wherethe photographer normally does not perform the finder observation of thesubject. Therefore, it is possible to prevent displacement of thesubject image due to the initializing operation from being seen by thephotographer.

There are the cases where, if the power supply 104 is removed, theinformation on the lens held by the camera control microcomputer 102till then is reset. If a new power supply 104 is loaded in this case,the camera control microcomputer 102 often requests the lens controlmicrocomputer 112 to transmit the lens ID.

For this reason, as in the first embodiment, the camera controlmicrocomputer 102 may determine the transmission of the lens ID andperform the initializing operation of the image-stabilizing unit 200.

[Fifth Embodiment]

The lens apparatus of the present invention may have animage-stabilizing unit other than the image-stabilizing unit having theconfiguration described in the first embodiment mounted thereon. Anexample thereof as the fifth embodiment of the present invention isshown in FIGS. 12 and 13.

In the image-stabilizing unit 200″ shown in FIGS. 12 and 13, a shiftlens-barrel 415 is biased on a shift base 413 side by three coil springs450 placed between three locations on the periphery of the shiftlens-barrel 415 and the shift base 413. It is thereby possible, as withthe image-stabilizing unit 200 of the first embodiment, to bring a ball416 into contact with the shift lens-barrel 415 and the shift base 413with pressure.

To securely prevent the shift lens-barrel 415 from rotating around theoptical axis, a guide shaft 460 for guiding the shift lens-barrel 415 inthe pitch direction and yaw direction may be used as shown in FIG. 14.

The guide shaft 460 has an L-shape when viewed in an optical axisdirection shown in FIG. 14. A yaw-direction shaft portion of the guideshaft 460 is engaged with catching parts 413 a provided on the shiftbase 413 while allowing movement of the guide shaft 460 in theyaw-direction. A pitch-direction shaft portion of the guide shaft 460 isengaged with catching parts 415 a provided on the shift lens-barrel 415while allowing movement of the guide axis 460 in the pitch-direction.

As described above, according to the above-described embodiments, theinitializing operation of the image-stabilizing unit (ball positions) isperformed when mounting the optical apparatus on another opticalapparatus, in a power-off state and when replacing the battery, that is,when the photographer is not observing the subject through the finder ingeneral. Consequently, it is possible to prevent displacement of thesubject image due to the initializing operation from being seen by thephotographer.

The preferred embodiments of the present invention were described above.However, the present invention is not limited to these embodiments butvarious modifications and changes are possible.

The present invention is also applicable to a lens apparatus mounted ona camera (a video camera for instance) which has no quick return mirrorand allows the subject image to be observed only by an electronic viewfinder.

Furthermore, the embodiments described the lens apparatus for performingthe image stabilization by driving the correction lens. However thepresent invention is also applicable to an image-pickup apparatus(optical apparatus) including an image-stabilizing unit which performsthe image stabilization by driving a movable unit including animage-pickup element for picking up a subject image. In this case, theimage-pickup apparatus performs the initializing operation of theimage-stabilizing unit when its own power switch is off or when thebattery is replaced.

Furthermore, the present invention is not limited to these preferredembodiments and various variations and modifications may be made withoutdeparting from the scope of the present invention.

This application claims foreign priority benefits based on JapanesePatent Application No. 2005-356592, filed on Dec. 9, 2005, which ishereby incorporated by reference herein in its entirety as if fully setforth herein.

1. An optical apparatus comprising: an image-stabilizing unit whichincludes a movable unit movable for image stabilization and ballsmovable in conjunction with the movement of the movable unit; and acontroller which controls operations of the movable unit, wherein thecontroller causes the movable unit to perform a reset operation formoving the balls to a movable center position, the reset operation beinga different operation than an image stabilization operation of theimage-stabilizing unit, and wherein the controller causes the movableunit to perform the reset operation in response to the controllerdetermining that a certain time period has elapsed after a power switchhas been turned off.
 2. An image-pickup system comprising: an opticalapparatus; and an image-pickup apparatus on which the optical apparatusis mounted, wherein the optical apparatus comprises: animage-stabilizing unit which includes a movable unit movable for imagestabilization and balls movable in conjunction with the movement of themovable unit; and a controller which controls operations of the movableunit, wherein the controller causes the movable unit to perform a resetoperation for moving the balls to a movable center position, the resetoperation being a different operation than an image stabilizationoperation of the image-stabilizing unit, and wherein the controllercauses the movable unit to perform the reset operation in response tothe controller determining that a certain time period has elapsed aftera power switch has been turned off.